The FBI was carefully examining Thursday the car and home of the gunman who killed 12 people at a bar in Thousand Oaks, Calif.

The shooter, Marine Corps veteran Ian David Long, 28, apparently killed himself after gunning down customers in the Borderline Bar and Grill. Investigators are looking for clues to Long’s “state of mind” before Wednesday’s late-night shooting.

Paul Delacourt, assistant director of the FBI’s Los Angeles office, said it appears Long acted alone.

“We’re going to pursue the leads that develop from that evidence, wherever they take us, to identify any possible motivation, paint a picture of the frame of mind of the subject, identify any possible radicalization,” Delacourt said Thursday.

People comfort each other as they stand near the scene, Nov. 8, 2018, in Thousand Oaks, Calif. where a gunman opened fire Wednesday inside a country dance bar crowded with hundreds of people.

​Brushes with law enforcement

Long had minor run-ins with the law previously, including a traffic accident and a bar fight, law enforcement officials said Thursday.

Earlier this year, police were called to his home after neighbors reported what officers described as a disturbance. At the time, police said Long “was somewhat irate, acting a little irrationally.”

Officers speculated Long, who had served in Afghanistan for seven months, was suffering from post-traumatic stress disorder. But a mental health professional who spoke with Long said he did not believe Long needed to be hospitalized.

Late Wednesday, the Borderline Bar and Grill was crowded with students who regularly attended its country music dance party.

Police say Long was dressed in black from head to toe. He shot a security guard, tossed smoke bombs into the bar and opened fire with a handgun equipped with a device that allowed it to hold more bullets.

Stunned, panicked and frightened customers ran for cover and hid wherever they could: in bathrooms, in the attic, behind a pool table. Some threw barstools through windows to escape.

Law enforcement officers salute the hearse carrying the body of Ventura County Sheriff Sgt. Ron Helus, who was shot and killed in a mass shooting at a bar in Thousand Oaks, Calif., Nov. 8, 2018.

The dead include a sheriff’s deputy who rushed into the bar in response to the shooting. Deputy Ron Helus was less than a year from retirement. Police and firefighters lined the highways and saluted as a hearse carried his body from a hospital to the country coroner’s office.

Wednesday night’s shooting came less than two weeks after a self-proclaimed anti-Semite was charged with killing 11 people in a Pittsburgh synagogue. That shooting came days after a gunman was suspected of killing two black patrons of a Kentucky supermarket after he apparently failed to get inside a black church.

These crimes follow the mass killing of 17 students at a Florida high school in February, and the massacre of 59 people at a Las Vegas music festival in October 2017.

Some of the Las Vegas survivors, who happened to be at the bar, also survived Wednesday’s shooting.

People wait in line to donate blood outside LaReina High School after a mass shooting by a lone gunman at a bar in Thousand Oaks, Calif., Nov. 8, 2018.

​Marine Corps offers condolences

“It’s a gun culture,” California’s Democratic Gov.-elect Gavin Newsom lamented Thursday. “You can’t go to a bar or a nightclub? You can’t go to church or a synagogue? It’s insane, is the only way to describe it. The normalization — that’s the only way I can describe it. It’s become normalized.”

The U.S. Marine Corps issued a statement extending “its deepest condolences to the families of the victims in this senseless tragedy.”

The Marine Corps said Long had attained the rank of corporal after serving nearly five years, including seven months in Afghanistan. He was a machine gunner and the recipient of numerous medals, including the Good Conduct Medal and the Combat Action Ribbon.

In a tweet, President Donald Trump applauded the response of police and extended blessings to the victims and their families. He also ordered American flags flown at half-staff in honor of the victims.

The top Democrat on the House Judiciary Committee, Jerry Nadler of New York, said lawmakers would start crafting a gun-control bill when the House convenes with a Democratic majority in early January.

“We must find a way to stop the senseless, and many times preventable killings that are robbing our country of innocent lives,” Nadler tweeted.

Thousand Oaks, California

Shootings are very rare in Thousand Oaks, a city of about 130,000 people about 64 kilometers west of Los Angeles. Thousand Oaks was considered the third-safest city in the U.S. this year, according to Niche, an online company that provides data on neighborhoods, companies and schools.